pngquant is a batch conversion utility to quantize and dither truecolor PNG images, especially those with a full alpha channel, down to "RGBA-palette" PNGs (i.e., PLTE + tRNS in PNG parlance). Such images are usually two to four times smaller than the full 32-bit versions, and partial transparency is preserved quite nicely. This makes pngquant especially useful both for Web sites and for PlayStation 2 development, where one of the texture formats is RGBA-palette-based (though not PNG-compressed).

DatePNG is a PHP class can be used to generate a PNG image with a given time. It opens a template image in PNG format and renders text with a time in one or more formats. The font, size, position, angle, and color of the text are configurable parameters. The resulting image is generated in the PNG format as the current script output.

ImageOptim decreases the file size of PNG, JPEG, and GIF images, even those "Saved for Web". It combines OptiPNG, PNGCrush, AdvanceComp, PNGOUT, Jpegoptim + Jpegtran, and Gifsicle for the best possible optimization.

Twibright Registrator removes noise and can quadruple the resolution of a camera in software by matching several pictures together. It can be applied to remove noise, JPEG artifacts, rain, CRT stripes, and passersby. It can enhance night photos and provide the effect of long exposure in daylight. Pictures are matched by removing shift, rotation, zoom, and brightness changes. It features high performance bilinear interpolation, automatic adaptive corrective deconvolution, 32-bit float depth, photometrically linear space, and 16-bit depth PNG output.

PHP-Identicons is a lightweight PHP implementation of Don Park's original identicon code for visual representation of MD5 hash values. The program uses the standard PHP GD library for image processing.

WS Charts is a PHP class that can be used to render charts of several types. It takes a list of values that define points of one or more sets and renders charts of several possible types: line, bar, surface, and pie. The class provides options to choose colors, gradients, show coordinates, etc. The generated charts can be saved to a given file or displayed as the current script output.

IMGCrush is an image compressor. IMGCrush_GUI is a simple GUI for IMGCrush. IMGCrush can perform both lossy and lossless compression in order to achieve the file size or quality that the user requires.

SVGpage is an application that will render PNG images as SVG files or convert an SVG file to a PNG image. It uses an internal version of Autotrace. This is not a straight conversion to SVG (as there really is no such converter) but it does a fairly literal job with simple shapes, and renders a "painterly" effect for more photographic-style images.

OpenIcons is a set of SVG icons intended to be used on the Web. All the icons are vector-based and made using InkScape. The icons can easily be converted from SVG to pretty much any common graphics format. Since the icons are meant to be used primarily on the Web, the default distribution of the icons includes PNG copies of all icons scaled to the following sizes: 16x16, 32x32, 64x64, and 128x128 pixels.